Vessel sealing devices

ABSTRACT

A device for temporarily sealing an opening in a blood vessel is provided. The device comprises a cutting mechanism for creating an opening in a blood vessel and a seal for sealing the opening in the blood vessel. The seal is delivered through an inner lumen of a tool body coupled to the cutting mechanism. Methods for using the device to construct an anastomosis between two vessels are also provided.

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.10/763,861, filed, Jan. 22, 2004 now abandoned.

FIELD OF THE INVENTION

The present invention relates to the field of medical methods anddevices for occluding and/or sealing incisions in vessels of the body.More particularly, the invention relates to devices that are capable ofcreating and sealing incisions in cardiac blood vessels in order tofacilitate a medical procedure, such as an anastomosis, on a stopped orbeating heart.

BACKGROUND OF THE INVENTION

The current leading cause of death in the United States is coronaryartery disease (CAD) which is the occlusion or blockage of the coronaryarteries by atherosclerotic plaques or fatty deposits. Occlusions in thecoronary arteries generally causes chest pain (angina) and/or heartattacks (myocardial infarction) due to a lack of blood flow, i.e.oxygen, to the tissues of the heart. The lack of oxygen in tissues ofthe heart causes myocardial ischemia. Severe and prolonged myocardialischemia can produce cardiac dysfunction, heart muscle damage andpossibly death.

One treatment to relieve a partially or fully blocked coronary artery iscoronary artery bypass graft (CABG) surgery. CABG surgery, also known as“heart bypass” surgery, generally entails the use of a graft or conduitto bypass the coronary obstruction and, thereby provide blood flow tothe downstream ischemic heart tissues. More particularly, a fluidconnection or “anastomosis” is surgically established between a sourcevessel of oxygenated blood and the obstructed or restricted targetcoronary artery downstream or distal to the obstruction or restrictionto restore the flow of oxygenated blood to the heart muscle. In oneapproach, the surgeon attaches an available source vessel, e.g., aninternal mammary artery (IMA), directly to the obstructed targetcoronary artery at the distal anastomosis site downstream from theobstruction or restriction.

Conventional CABG procedures are typically conducted on a cardioplegicarrested heart while the patient is on cardiopulmonary bypass (CPB). Astopped heart and a CPB circuit enable a surgeon to work in a relativelymotionless, bloodless operative field, however there are a number ofproblems associated with CABG procedures performed while on CPB. Forexample, problems associated with conventional CABG procedures mayinclude the initiation of a systemic inflammatory response due to theinteractions of blood elements with the artificial material surfaces ofthe CPB circuit, global myocardial ischemia due to global (hypothermic)cardiac arrest, and post-operative stroke due to clamping of the aorta.In addition, the use of a partial side-biting aortic clamp used toisolate a portion of the aorta can also cause trauma to the patient. Theuse of clamps can add to the time required for performing the procedure,as well as the use of clamps may dislodge plaques from the vessel beingclamped resulting, for example, in neurologic injury. The clampingpressure can also cause damage to the endothelial lining of the aorta.Post-operative scarring can provide an irregular surface causingincreased plaque build up.

Obstructed coronary arteries are generally bypassed; for example, withan in situ internal mammary artery (IMA) or a reversed segment ofsaphenous vein harvested from a leg. Segments of other suitable bloodvessels may also be used for grafting depending on availability, sizeand quality. In general, the body hosts seven potential arterialconduits, the right and left IMAs, the radial arteries and three viceralarteries, one in the abdomen, and two in the lower abdominal wall,though the latter may be quite short and are generally of limitedusefulness. The viceral arteries include the gastroepiploic artery andthe splenic artery.

The left IMA is best used for bypass to the left anterior descending(LAD) coronary artery and its diagonal branches. Whereas, the right IMAmay be used for bypass to selected vessels more posterior such as thedistal right coronary artery (RCA). The right IMA may also be used forbypass to selected marginal branches of the left circumflex coronaryartery. A segment of radial artery harvested from an arm is generallyused to revascularize the posterior surface of the heart. The rightgastroepiploic artery may be used to revascularize almost any artery onthe surface of the heart. It is most commonly used for bypass to thedistal RCA or the posterior descending coronary artery. In unusualcircumstances the splenic artery is used to revascularize posteriorcoronary arteries, but it is long enough to reach the marginal branchesof the circumflex coronary artery.

Surgeons generally complete bypass grafts to the following coronaryarteries in a patient undergoing multiple bypass surgery in roughly thefollowing order: posterior descending coronary artery (PDA), RCA, obtusemarginal branch, circumflex coronary artery, diagonal branch, and LAD.More generally, surgeons will revascularize the three coronary systemsin the following order: right, circumflex, and anterior descending.However, the order may vary depending on whether the procedure isperformed on a beating heart or an arrested heart. For arrested heart,about 3 to 4 bypass grafts of which 1 to 3 are free grafts are generallyperformed per procedure. In contrast, about 2 to 3 bypass grafts ofwhich 0 to 2 are free grafts are generally performed per beating heartprocedure. In general, 1 free graft is used per beating heart procedure.

When a saphenous vein or other blood vessel is used as a free graft in aprocedure, two anastomoses are performed; one to the diseased arterydistal to the obstruction (outflow end), and one proximally to the bloodvessel supplying the arterial blood (inflow end). These anastomoses aregenerally performed using end-to-side and/or side-to-side anastomotictechniques. Rarely an end-to-end anastomotic technique is used. Whenmore than one graft is required in any of the three coronary systems forcomplete revascularization of the heart, sequential graft techniques maybe used to conserve the amount of blood vessels required. Sequentialgraft techniques use proximal side-to-side anastomoses and anend-to-side anastomosis to complete the graft. For example, a commonsequence used in the anterior descending coronary system is aside-to-side anastomosis of graft to the diagonal branch and anend-to-side anastomosis of graft to the LAD coronary artery.

The majority of surgeons will complete the distal anastomosis of a graftprior to completion of the proximal anastomosis. The small percentage ofsurgeons who do complete the proximal anastomosis first usually do so toallow antegrade perfusion of cardioplegic solution through the graftduring revascularization. Construction of the distal anastomosis, e.g.,a saphenous vein-coronary artery anastomosis, begins by first locatingthe target artery on the heart. Next, an incision is made through theepicardium and the myocardium to expose the artery. An arteriotomy isthen made using a knife to incise the artery. The incision is thenextended with a scissors. The length of the incision approximates thediameter of the saphenous vein, about 4 to 5 mm. The diameter of thetarget artery is generally 1.5 to 2.0 mm. Since, most surgeons feel thedistal take-off angle should be 30 to 45 degrees, the distal end of thesaphenous vein is beveled at about 30 to 45 degrees.

Most surgeons construct the anastomosis via a ten-stitch running sutureusing 7-0 polypropylene suture material. The ten-stitch anastomosistypically comprises five stitches around the heel of the graft and fivestitches around the toe. The five stitches around the heel of the graftcomprise two stitches to one side of the apex of the graft and theartery, a stitch through the apex and two stitches placed at theopposite side of the apex. The graft is generally held apart from thecoronary artery while the stitches are constructed using a needlemanipulated by a forceps. Suture loops are drawn up and the suturepulled straight through to eliminate purse-string effect. The fivestitches around the toe of the graft also comprises two stitches to oneside of the apex of the graft and the artery, a stitch through the apexand two stitches placed at the opposite side of the apex. Again, sutureloops are drawn up and the suture pulled straight through to eliminatepurse-string effect. The suture ends are then tied.

The proximal anastomosis of a saphenous vein graft to the aorta, i.e.,an aortosaphenous vein anastomosis, is generally formed by firstremoving the pericardial layer that covers the aorta. An occluding orside-biting clamp may be placed on the aorta at the anastomosis site. Asmall circular or elliptical portion of the ascending aorta is excisedforming a small opening 4 to 5 mm in diameter. An aortic punch typicallyfacilitates this procedure. The opening for a right-sided graft is madeanterior or to the right lateral side of the aorta, whereas an openingfor a left-sided graft is made to the left lateral side of the aorta. Ifthe graft is to supply blood to the right coronary artery, the openingis made proximal on the aorta. If the graft is to supply blood to theanterior descending coronary artery, the opening is made in the middleon the aorta. And, if the graft is to supply blood to the circumflexartery, the opening is made distal on the aorta. The right graft openingis placed slightly in the right of the anterior midpoint of the aortaand the left graft opening slightly to the left. The end of thesaphenous vein is cut back longitudinally for a distance ofapproximately 1 cm. A vascular clamp is placed across the tip of thesaphenous vein to flatten it, thereby exposing the apex of the vein.Five suture loops of a running suture using 5-0 polypropylene are thenplaced around the ‘heel’ of the graft and passed through the aorticwall. Two stitches are placed on one side of the apex, the third stitchis placed precisely through the apex of the incision in the saphenousvein, and the final two stitches are placed on the opposite side of theapex. Suture traction is used to help expose the edge of the aorticopening to ensure accurate needle placement. Stitches include about 3 to5 mm of the aortic wall for adequate strength. Suture loops are thenpulled up to approximate the vein graft to the aorta. The remainingstitches are placed in a cartwheel fashion around the aortic openingthereby completing the remainder of the anastomosis.

Left-sided grafts are oriented so the apex of the incision in the “heel”of the saphenous vein will face directly to the left side. The stitchesare placed in a clockwise fashion around the heel of the graft and in acounterclockwise fashion around the aortic opening. Right-sided graftsare oriented in a caudal fashion. The stitches are placed in acounterclockwise fashion around the heel of the graft and in a clockwisefashion around the aortic opening. Five suture loops complete the heelportion of the graft and an additional five or six are necessary tocomplete the toe of the graft. Finished proximal anastomoses usuallyhave a “cobra-head” appearance.

It is essential for the surgeon to take steps to minimize thepossibility of thrombosis, narrowing and/or premature closure of theanastomosis due to technical errors. Some surgeons feel the proximalanastomosis must have a take-off angle of 45 degrees while othersurgeons believe the take-off angle is not critical. In addition, it isgenerally felt that intima-to-intima contact of the vessels at theanastomosis is advantageous for endothelization to occur, thereby makingan ideal union of the vessels. However, intima-to-adventitia contact isacceptable by most surgeons. The main objective of the surgeon is tocreate an anastomosis with an expected long-term patency rate of greaterthan 5 to 10 years. The creation of an anastomosis takes approximately10 to 15 mins.

One essential requirement for creating a sutured anastomosis withouterror is adequate exposure. Acute visualization of the vessel walls ismandatory in order to properly place each stitch and avoid inadvertentlyincluding the back wall of the vessel in a stitch, which in effectnarrows or completely occludes the vessel. In order to achieve therequired exposure most surgeons will employee blood-less field devicessuch as shunts, snares, and misted blowers. Further, largely invasivesurgical techniques are also employed to help the surgeon gain access tothe grafting site. For this reason, CABG surgery is typically performedthrough a median stemotomy, which provides access to all major coronarybranches. A median stemotomy incision begins just below the sternalnotch and extends slightly below the xiphoid process. A sternalretractor is used to separate the sternal edges for optimal exposure ofthe heart. Hemostasis of the sternal edges is typically obtained usingelectrocautery with a ball-tip electrode and a thin layer of bone wax.

Currently, the golden standard for creation of a vascular anastomosis ismanual suturing. Manual suturing may be used to attach vascular grafts(either autografts or prosthetic grafts) for coronary bypass,femoral-femoral bypass (to relieve inadequate circulation in the legs),and AV fistulas and/or shunts (access portals for repeated punctureapplications such as kidney dialysis or diabetes). However, a number ofcardiac surgical procedures, e.g., off-pump, beating heart CABGprocedures, minimally invasive procedures and even totally endoscopicprocedures with access through ports only, may require a variety of newanastomotic techniques. The ability of performing anastomoses withlimited or no CPB support may increase the possibility of performingmore CABG procedures using minimally invasive surgical techniques.Avoiding the use of cross clamps and CPB or dramatically reducing pumprun and cross clamp times may effectively minimize post-operativecomplications. For this reason, there is an increasing need for easier,quicker, less damaging, but reliable automated, semi-automated, or atleast facilitated methods to replace or enhance the normal process of amanually sutured vascular anastomosis.

The major objective of any CABG procedure is to perform a technicallyperfect anastomosis. However, creation of a technically perfectanastomosis is generally complex, tedious, time consuming and itssuccess is highly dependent on a surgeon's skill level. Therefore,creation of vascular anastomoses without the need to perform delicateand intricate suture lines may enable surgeons to more quickly createsimpler and effective anastomoses. Currently, there are a number oftechniques or procedures being investigated for facilitating the processof forming an anastomosis including vascular clips or staples, glues,adhesives or sealants, laser welding, mechanical couplers, stents androbot-assisted suturing. These techniques are being developed forperforming end-to-end, end-to-side and/or side-to-side anastomoses withor without temporary blood flow interruption. In general, thesetechniques may include the use of various biomaterials and/orbiocompatible agents.

There are a number of alternative approaches to CABG surgery. In oneapproach, the surgeon harvests a graft blood vessel from the patient andprepares its proximal and distal ends to be attached in a “proximalanastomosis” and a “distal anastomosis” bypassing the occlusion. Thistype of graft is commonly known as a “free” graft. The proximalanastomosis can be located proximal or upstream to the occlusion or toanother vessel supplying oxygenated blood, e.g., the aorta. Typically, asection of the saphenous vein or radial artery is harvested from thepatient's body and used as a free graft. The opening in the aorta, theaortotomy, is typically made by removing the pericardial layer coveringthe aorta, creating a small (less than 5 mm) incision through the layersof aortic wall, inserting an aortic punch into the incision and finallyactuating the punch to create a round hole. This hole is made into theaorta to provide arterial blood to the bypass graft. To achieve the bestflow dynamics, the hole created by the punch should have smooth edges.In addition, the aortic tissue may be very tough to puncture, therebyrequiring some effort to produce an acceptable aortotomy.

In another approach, a portion of the left IMA or right IMA is dissectedaway from supporting tissue and severed so that the severed end can beanastomosed to the obstructed coronary artery distally to the stenosisor occlusion. More recently, other arteries have been used in “attached”graft procedures, including the inferior epigastric arteries andgastroepiploic arteries. It is also stated in U.S. Pat. No. 6,080,175that a conventional electrosurgical instrument can be introduced througha port or incision and used to dissect and prepare the bypass graftvessel for coronary anastomosis while viewing the procedure through athoracoscope.

It is necessary to access and prepare the site or sites of the vesselwall of the target coronary artery where the proximal and/or distalanastomosis is to be completed and to then make the surgical attachmentsof the blood vessels. First, it is necessary to isolate the anastomosissite of the target coronary artery from the epicardial tissues andoverlying fatty layers. Typically, blunt, rounded #15 scalpel blades areemployed to dissect these tissues and layers away from the targetcoronary artery.

Generally, blood flow in the target coronary artery is interrupted by,for example, temporary ligation or clamping of the artery proximaland/or distal of the anastomosis site, and the target coronary arterywall is opened to form an arteriotomy, that is, an elongated incision atthe anastomosis site extending parallel to the axis of the coronaryvessel and equally spaced from the sides of the coronary artery that arestill embedded in or against the epicardium. The arteriotomy istypically created by use of a very sharp, pointed, #11 scalpel blade toperforate the coronary artery wall, and the puncture is elongated therequisite length using scissors. A “perfect arteriotomy” is an incisionthat has straight edges, that does not stray from the axial alignmentand equal distance from the sides of the coronary artery, and is of therequisite length.

Similarly, it is necessary to prepare the attachment end of the sourcevessel by cutting the source vessel end at an appropriate angle for anend-to-side or end-to-end anastomosis or by forming an elongatedarteriotomy in the source vessel wall of a suitable length that isaxially aligned with the source vessel axis for a side-to-sideanastomosis. Typically, the surgeon uses surgical scalpels and scissorsto shape the source vessel end or make the elongated arteriotomy slit inthe source vessel, and uses sutures or clips to close the open severedend.

In the example depicted schematically in FIG. 1, the heart 12 isprepared as described above for an end-to-side anastomosis of thesurgically freed, severed, and appropriately shaped vessel end 31 of theleft IMA 30 branching from the aorta 16 and left subclavian artery 18 tothe prepared arteriotomy 15 in the vessel wall of the left anteriordescending (LAD) coronary artery 14 downstream from the obstruction 38.Similarly, in the example depicted schematically in FIG. 3, the heart 12is prepared as described above for a side-to-side anastomosis of theleft IMA 30 to the prepared arteriotomy 15 in the vessel wall of the LADcoronary artery 14. In the side-to-side anastomosis, an arteriotomy 33is made in the freed segment of the left IMA 30, and the vessel end 31is sutured closed. In the example depicted schematically in FIG. 5, theheart 12 is prepared as described above for an end-to-side anastomosisof the surgically harvested, and appropriately shaped vessel end 41 ofthe free graft 40, e.g., a saphenous vein or radial artery segment, tothe prepared arteriotomy 15 in the vessel wall of the LAD coronaryartery 14 downstream from the obstruction 38. In addition, the heart 12is prepared as described above for an end-to-side anastomosis of theappropriately shaped vessel end 42 of the free graft 40 to the preparedaortotomy 43 in the wall of the aorta 16.

The prepared end or elongated arteriotomy of a bypass graft or sourcevessel is attached or anastomosed to the target coronary artery or aortaat the arteriotomy or aortotomy in a manner that prevents leakage ofblood employing sutures, staples, surgical adhesives and/or variousartificial anastomosis devices. For example, an end-to-side anastomosis35 of the shaped vessel end 31 of the left IMA 30 to the preparedarteriotomy 15 in the vessel wall of the LAD coronary artery 14 isillustrated in FIG. 2. And a side-to-side anastomosis 37 joining thearteriotomy 33 of the left IMA 30 to the prepared arteriotomy 15 of theLAD coronary artery 14 is illustrated, for example, in FIG. 4. And anend-to-side anastomosis 35 of the shaped vessel end 41 of the free graft40 to the prepared arteriotomy 15 in the vessel wall of the LAD coronaryartery 14 is illustrated in FIG. 6. In addition, an end-to-sideanastomosis 47 of the shaped vessel end 42 of the free graft 40 to theprepared aortotomy 43 in the wall of the aorta 16 is also illustrated inFIG. 6. Alternatively, anastomoses 35 and 47 may be constructed asside-to-side anastomoses, if so desired.

The inner, endothelial layer, vessel linings are less thrombogenic thanthe outer epithelial layers of blood vessels. So, in one approach, theattachment is made by everting and applying the interior linings of thebypass graft or source vessel and the target coronary artery against oneanother and suturing or gluing or otherwise attaching the interiorlinings together. Various types of artificial biocompatiblereinforcement sleeves or rings may also be used in the anastomosis.Currently, a number of mechanical anastomotic devices, materials,techniques, and procedures are being developed for facilitating theprocess of forming an anastomosis including vascular clips or staples,glues, adhesives or sealants, laser welding, mechanical couplers, stentsand robot-assisted suturing. These techniques are being developed forperforming end-to-end, end-to-side and/or side-to-side anastomoses withor without temporary blood flow interruption. In general, thesetechniques can include the use of various biomaterials and/orbiocompatible agents. See, for example, U.S. Pat. Nos. 5,385,606,5,695,504, 5,707,380, 5,972,017 and 5,976,178, and 6,231,565.

Various examples of forming the target vessel arteriotomy orarteriotomies, the shaped end or side wall arteriotomy of the sourcevessel, and the positioning and attachment of the source vessel andtarget artery together are set forth in U.S. Pat. Nos. 5,776,154,5,799,661, 5,868,770, 5,893,369, 6,026,814, 6,071,295, 6,080,175,6,248,117, 6,331,158, and 6,332,468.

In a conventional bypass graft or CABG procedure, the surgeon exposesthe obstructed coronary vessel through an open chest surgical exposureor stemotomy providing direct visualization and access to theepicardium. Typically, fat layers that make it difficult to see eitherthe artery or the occlusion cover the epicardial surface and theobstructed cardiac artery. However, surgeons are able to dissect the fataway to expose the artery and manually palpate the heart to feel therelatively stiff or rigid occlusion within the artery as a result oftheir training and experience. The surgeon can determine the locationand length of the occlusion as well as suitable sites of the targetcoronary artery for the proximal and distal anastomoses with some degreeof success.

The open chest procedure involves making a 20 to 25 cm incision in thechest of the patient, severing the sternum and cutting and peeling backvarious layers of tissue in order to give access to the heart andarterial sources. As a result, these operations typically require largenumbers of sutures or staples to close the incision and 5 to 10 wirehooks to keep the severed sternum together. Such surgery often carriesadditional complications such as instability of the sternum,post-operative bleeding, and mediastinal infection. The thoracic muscleand ribs are also severely traumatized, and the healing process resultsin an unattractive scar. Post-operatively, most patients enduresignificant pain and must forego work or strenuous activity for a longrecovery period.

Many minimally invasive surgical techniques and devices have beenintroduced in order to reduce the risk of morbidity, expense, trauma,patient mortality, infection, and other complications associated withopen chest cardiac surgery. Less traumatic limited open chest techniquesusing an abdominal (sub-xyphoid) approach or, alternatively, a“Chamberlain” incision (an approximately 8 cm incision at thestemocostal junction), have been developed to lessen the operating areaand the associated complications. In recent years, a growing number ofsurgeons have begun performing CABG procedures while the heart is stillbeating using minimally invasive direct coronary artery bypass grafting(MIDCAB) surgical techniques and devices. Using the MIDCAB method, theheart typically is accessed through a mini-thoracotomy (i.e., a 6 to 8cm incision in the patient's chest between the ribs) that avoids thestemal splitting incision of conventional cardiac surgery. A MIDCABtechnique for performing a CABG procedure is described in U.S. Pat. No.5,875,782, for example.

Other minimally invasive, percutaneous, coronary surgical procedureshave been advanced that employ multiple small trans-thoracic incisionsto and through the pericardium, instruments advanced through sleeves orports inserted in the incisions, and a thoracoscope to view the accessedcardiac site while the procedure is performed as shown, for example, inthe above-referenced '175, '295, '468 and '661 patents and in U.S. Pat.Nos. 5,464,447, and 5,716,392. Surgical trocars having a diameter ofabout 3 mm to 15 mm are fitted into lumens of tubular trocar sleeves orports, and the assemblies are inserted into skin incisions. The trocartip is advanced to puncture the abdomen or chest to reach thepericardium, and the trocar is then withdrawn leaving the port in place.Surgical instruments and other devices such as fiber optic thoracoscopescan be inserted into the body cavity through the port lumens. As statedin the '468 patent, instruments advanced through trocars can includeelectrosurgical tools, graspers, forceps, scalpels, electrocauterydevices, clip appliers, scissors, etc.

In an endoscopic approach, the surgeon may stop the heart by utilizing aseries of internal catheters to stop blood flow through the aorta and toadminister cardioplegia solution. The endoscopic approach utilizes groincannulation to establish CPB and an intraaortic balloon catheter thatfunctions as an internal aortic clamp by means of an expandable balloonat its distal end is used to occlude blood flow in the ascending aorta.A full description of an example of one preferred endoscopic techniqueis found in U.S. Pat. No. 5,452,733, for example.

In an attempt to eliminate problems associated with CPB, “beating heart”procedures that eliminate the need for CPB have been developed. Surgicalinstruments that attempt to stabilize or immobilize a portion of thebeating heart that supports the target coronary artery and theanastomosis site have been developed. These beating heart procedures andinstruments described, for example, in the above-referenced '158, '175,'770, '782, and '295 patents and in U.S. Pat. Nos. 5,976,069, and6,120,436, can be performed on a heart exposed in a full or limitedthoracotomy or accessed percutaneously.

For example, a retractor assembly disclosed in the above-referenced '158patent mounts to and maintains the chest opening while supporting astabilizer assembly that extends parallel stabilizer bars against theepicardium alongside the target coronary artery so that force is appliedacross the anastomosis site to suppress heart motion. The surgeonemploys conventional manually applied clamps to block blood flow throughthe arterial lumen and scalpels and scissors to make the elongatedincision of the arteriotomy.

Instruments are disclosed in the above-referenced '295 patent that applysuction to the epicardial surface around or alongside the anastomosissite to suppress heart motion. Again, the surgeon employs theconventional manually applied clamps to block blood flow through thearterial lumen and a scalpel to make the elongated incision of thearteriotomy.

Beating heart surgical methods still use clamps and thus, still presentthe problems associated with clamps described above. For example, thecommon practice in beating heart surgical methods is to use a side-clamprather than a cross-clamp. Beating heart surgical methods still requirethe creation of anastomosis and thus still require an aortotomy. Thusbeating heart surgical methods still present the time constraints anddifficulties associated with creating an effective anastomosis, such asdifficulty creating an aortotomy hole with smooth edges and potentialtrauma resulting from clamping.

Several attempts have been made to create devices that occlude thevessel without using clamps or devices that maintain hemostasis of theaortotomy or arteriotomy during creation of an anastomosis.

U.S. Pat. Nos. 6,132,397 and 6,068,608 to Davis describes an aortic archclamp catheter which occludes the ascending aorta using an expandableballoon rather than a cross clamp.

U.S. Pat. No. 6,165,196 to Stack et al. describes an occlusion apparatuswith two occluding members and a shield that resists perforation.

U.S. Pat. No. 5,766,151 to Valley et al. describes a modifiedendovascularly inserted, internal vascular clamp to be used within thevessel instead of the external cross clamp.

Other methods and devices are described for creating effectiveanastomoses.

U.S. Pat. No. 6,193,734 to Bolduc et al. describes a device for creatinganastomoses using a tissue securing member movable from a first tosecond configuration which movement causes a compressive force to beapplied to the vessels to be joined.

U.S. Pat. No. 6,234,995 to Peacock describes a modified arterialcatheter with a distal end portion that may be positioned within theaortic root adjacent to the left ventricle and a proximal portion thatis coupled to a bypass pump.

U.S. Pat. No. 6,395,015 to Borst et al. and assigned to Medtronicdescribes a temporary intravascular arteriotomy seal for insertion intoand retrieval from a blood vessel through an opening in the wall of thevessel.

U.S. Pat. No. 6,171,319 to Nobles and Baladi describes a devicecomprising an inverting member adapted to be inserted through a smallincision in a blood vessel while the inverting member is maintained inan elongated, narrow configuration. A seal is then formed by applying aproximal force to the inverting member which has been inverted into anexpanded, inward-facing cup following insertion into the blood vessel.The rim of the cup forms a seal against the inner wall of the bloodvessel, thereby preventing blood from flowing out of the incision.

Instruments that combine the application of suction to the epicardialsurface around or alongside the anastomosis site to suppress heartmotion with a cutting mechanism for making the arteriotomy are disclosedin the above-referenced '175 and '770 patents. The surgical cuttinginstruments disclosed in the '770 and '175 patents include an elongatedshaft having a proximal end, a distal end adapted for percutaneousinsertion against the target coronary artery over the anastomosis site,and an axial lumen therebetween. A suction pad is formed at the distalend of the shaft, and a cutting element disposed within the lumen of theshaft near the distal end. A vacuum line is fluidly coupled to the lumenof the shaft and is adapted to connect to a vacuum source to effect asuction force at the distal end of the shaft. A control mechanism isprovided to selectively block flow between the vacuum source and thelumen. The control mechanism may include a slide valve, an on/offbutton, or other equivalent mechanism for selectively closing andopening the vacuum pathway. A gripper assembly configured to grip aportion of the coronary artery is also disclosed in the '175 patent.

The cutting element and the shaft are relatively moveable between aretracted position and a cutting position. The cutting element isadapted to make the elongated slit of the arteriotomy in alignment withthe axis of the coronary artery when the cutting element and the shaftare in the cutting position and the vacuum holds the anastomosis sitesteady.

The distal end of the shaft disclosed in the '175 patent has an outsidediameter of less than about 5 mm, and the cutting element comprises atleast one cutting element having a substantially straight blade cuttingedge. The cutting edge is displaced at an angle of between about 15 to30 degrees relative to a vertical axis through the cutting element. Inone embodiment, the cutting element is fixed to an actuator push rodlocated within the lumen of the shaft, and connected to an actuator,preferably an actuator button, at a proximal end thereof. In anotherembodiment, the shaft is slidably mounted to a handle of the cuttinginstrument. An anchor, preferably a rigid rod coaxially disposed withinthe shaft, fixes the cutting element to the handle. An actuator membermounted to the shaft and biased by a spring is actuated to slide theshaft between retracted and cutting positions with respect to thecutting element.

Additionally or alternatively, at least one electrode may be disposednear the distal end of the shaft to effect or enhance cutting. Theelectrode may be operatively coupled to the cutting element, preferablysubstantially co-linearly coupled to the cutting edge. In the depictedembodiments, the electrode extends to the sharpened tip of the cuttingelement opposite to the cutting blade. In use, the end of the electrodeat the tip of the cutting element is placed against the coronary arteryand energized by radio frequency energy as the cutting element is movedto the cutting position to facilitate making a small point incision orpilot hole in the coronary artery. Then, the cutting blade is fullyadvanced to make the elongated cut. Ultrasonic energy may be applied tothe cutting element to effect or enhance cutting by the ultrasonicallyvibrating the cutting blade.

The approaches described above for making an arteriotomy employ acutting blade to make the elongated slit. In most cases, the shaft mustbe carefully moved to advance the cutting blade along the length of thevessel wall without inadvertently pushing the tip of blade across thevessel lumen and through the vessel wall opposite to the intended slit.Damage can be caused to the vessel wall if care is not taken.

An instrument or tool is needed for making an arteriotomy, an aortotomyor a similar incision in a vessel wall that avoids or minimizes the lossof blood through the incision.

An instrument or tool is needed that inhibits blood loss through theincision as an anastomosis is being made.

An instrument or tool is needed that reduces or eliminates the need forclamps.

An instrument or tool is also needed that reduces the time for creatingan anastomosis.

All the publications and patents described above are hereby incorporatedby reference herein in their respective entireties. As those of ordinaryskill in the art will appreciate readily upon reading the Summary of theInvention, the Detailed Description of the Preferred Embodiments and theClaims set forth below, many of the devices and methods disclosed abovemay be modified advantageously by using the teachings of the presentinvention.

SUMMARY OF THE INVENTION

The present invention is preferably embodied in methods and devices forcreating and sealing openings in vessels, e.g., coronary arteries. Inaccordance with one aspect of the present invention a device forcreating an opening in a first blood vessel and for sealing the openingin the first blood vessel while an anastomosis is created between thefirst blood vessel and a second blood vessel comprises a cuttingmechanism for creating the opening in the first blood vessel and a sealfor sealing the opening in the first blood vessel. In one embodiment ofthe present invention, the cutting mechanism comprises one or moreelectrodes.

In accordance with another aspect of the present invention a method ofconstructing an anastomosis between a first vessel and a second vesselcomprises a device having a cutting mechanism for creating an opening ina vessel and a seal for sealing the opening in the vessel. In oneembodiment of the present invention, the cutting mechanism comprises oneor more electrodes that can be used to form an opening in the vessel. Inone embodiment of the present invention, the seal may be delivered in afirst configuration into the opening in a vessel. The seal may also bedeployed to a second configuration to seal the opening.

In accordance with one aspect of the present invention a method anddevice for performing the method of making an opening into a vessel of apatient comprises accessing the outer surface of the vessel wall,applying a ground electrode in contact with the body of the patient,applying an electrosurgical cutting electrode to the outer surface ofthe vessel wall and applying RF energy between the electrosurgicalcutting electrode and the ground electrode at an energy level and for aduration sufficient to cut an opening through the vessel wall where theelectrosurgical cutting electrode is applied to the outer surface of thevessel wall.

This summary of the invention has been presented here simply to pointout some of the ways that the invention overcomes difficulties presentedin the prior art and to distinguish the invention from the prior art andis not intended to operate in any manner as a limitation on theinterpretation of claims that are presented initially in the patentapplication and that are ultimately granted.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of the preparation of a source vesselfree end and an arteriotomy in a coronary artery downstream from anobstruction for an end-to-side anastomosis;

FIG. 2 is a schematic illustration of the end-to-side anastomosis of thesource vessel free end to the arteriotomy in the coronary artery;

FIG. 3 is a schematic illustration of the preparation of a source vesselfree end and an arteriotomy in a coronary artery downstream from anobstruction for a side-to-side anastomosis;

FIG. 4 is a schematic illustration of the side-to-side anastomosis ofthe arteriotomy in the source vessel to the arteriotomy in the coronaryartery;

FIG. 5 is a schematic illustration of the preparation of the ends of afree graft and an arteriotomy in a coronary artery downstream from anobstruction for an end-to-side anastomosis and an aortotomy in the wallof an aorta;

FIG. 6 is a schematic illustration of the end-to-side anastomosis of oneend of the free graft to the arteriotomy in the coronary artery and theend-to-side anastomosis of the other end of the free graft to theaortotomy in the aorta;

FIG. 7 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 8 a is a schematic diagram of one embodiment of an occluding devicein a first configuration for use in accordance with the presentinvention;

FIG. 8 b is a schematic diagram of the occluding device of FIG. 8 a in asecond configuration for use in accordance with the present invention;

FIG. 9 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 10 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 11 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 12 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 13 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 14 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 15 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 16 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 17 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 18 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 19 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 20 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 21 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 22 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 23 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 24 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 25 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 26 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 27 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 28 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 29 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 30 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 31 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 32 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 33 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 34 is a schematic diagram of one embodiment of a vessel sealingdevice in accordance with the present invention;

FIG. 35 is a flow diagram of one embodiment of a method for sealing avessel in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following detailed description, references are made toillustrative embodiments for carrying out the invention. It isunderstood that other embodiments may be utilized without departing fromthe scope of the invention.

For example, while a preferred method of forming arteriotomies incoronary arteries and aortotomies in the aorta in the process ofperforming anastomoses in a CABG procedure will be described herein, itis to be understood that the principles of the present invention may beapplied to a wide variety of surgical procedures, both conventionalprocedures, as well as minimally invasive procedures.

Vessel sealing devices or instruments of the present invention, forexample, may comprise elements for forming arteriotomies and/oraortotomies in vessel walls through the passage of a radio frequency(RF) energy between an active cutting electrode applied to the vesselwall and a ground pad contacting the patient's skin or a groundelectrode introduced into the vessel lumen. The RF energy or currentcuts tissue at the active cutting electrode, the cutting rate beingdependent on current density through the tissue contacted by the activecutting electrode. Rapid, clean edge incisions are made through thevessel wall when current density exceeds a threshold that causes thefluid within the cells to turn to steam, creating a sufficientoverpressure so as to burst the cell walls. The cells then dry up,desiccate, and carbonize, resulting in localized shrinking and anopening in the tissue.

Current density depends upon the area the active cutting electrodepresents to the vessel wall, the series impedance, typically resistance,to current flow between the active and ground pad or ground electrode,and the voltage applied to the series impedance. Current density isinversely proportional to active electrode contact area, so currentdensity increases as active electrode surface area decreases. Thecurrent density is typically adjusted by varying the voltage applied tothe active electrode since the area of a particular electrosurgicalinstrument active electrode is fixed and the series impedance cannotalways be controlled.

The series impedance is dependent upon several factors including thematerial and design of the active cutting electrode, the type, thicknessand conductivity of tissue and fluid between the active cuttingelectrode and the ground pad or electrode, the intimacy of contact ofthe cutting electrode with the tissue to be cut, and the location of thegrounding pad or electrode relative to the cutting electrode. RF energygenerators used in this type of surgery have a wide range of poweroutput to accommodate a variety of procedures and devices. For example,the RF energy generator can be adjusted to either cut tissue or tomerely cauterize previously cut or tom tissue.

The objective in electrosurgical tissue cutting is to heat the cells ofthe tissue so rapidly that they explode into steam leaving a cavity inthe cell matrix. The heat is meant to be dissipated in the steam and notto dry out adjacent cells. When the electrode is moved and fresh tissueis contacted, new cells are exploded, and the incision is made orcontinued. The electrical current utilized in electrosurgical cutting isin the radio frequency range and operates by jumping across an air gapto the tissue. This is commonly referred to as sparking. An explanationof electrosurgical cutting theory can be found in the FORCE 1Instruction Manual published by Valleylab, Inc. of Boulder, Colo., anddated Mar. 1, 1986.

In accordance with the present invention, instruments and methods areprovided that can be used in any of the above described full exposuresurgical procedures or less invasive MIDCAB or percutaneous exposures ofthe vessels in question, particularly, the above-described CABGprocedures on a stopped or beating heart.

FIG. 7 shows one embodiment of a vessel sealing device in accordancewith the present invention at 100. Vessel sealing device 100 comprises acutting mechanism 140 located at the proximal end of device 100. Cuttingmechanism 140 is used to create an incision or opening in a vessel wallthrough which occluding device or seal 110 and tether 114 are delivered.As seen in FIG. 7, some embodiments of vessel sealing device 100comprise elements that enable sealing device 100 to use electricalenergy, e.g., RF energy, or other suitable energy. For example, in FIG.7 cutting mechanism 140 comprises an electrode. Vessel sealing device100 further comprises a power conductor 145 to conduct power to cuttingelectrode 140. Power conductor 145 may be connected to a power source bypower connector pin 147. As described above, delivery shaft 130 is usedto deliver seal 110 and seal tether 114 through and out of inner lumen136 of tool body 135. Prior to delivery of seal 110, tether 114 residesin lumen 137 of shaft 130. In addition, cutting mechanism 140 is fixedto the proximal end of tool body 135. Preferably shaft 130 and tool body135 are made of one or more non-conductive materials.

Power conductor 145 may be any suitable power conductor for deliveringsufficient energy to cutting mechanism 140. For example, power conductor145 may comprise one or more metal wires. Power connector pin 147 may beany suitable connector that connects conductor 145 to a suitable powersource.

FIGS. 8 a and 8 b show one embodiment of a seal 110 for use inaccordance with the present invention. For example, seal 110 may be usedwith vessel sealing device 100. As seen by comparing FIGS. 8 a and 8 b,seal 110 may be constructed so that it is deployed in the configurationof FIG. 8 a and then, once placed, attains the configuration shown inFIG. 8 b.

Seal 110 may be formed of any suitable biocompatible material, forexample, a biocompatible polymer, which is impervious to blood. Abiocompatible material would prompt little allergenic response and wouldbe resistant to corrosion when placed within the patient's body.Alternatively, seal 110 may be a material of suitable flexibility, whichis coated with a biocompatible coating.

In one embodiment of the invention, seal 110 may be comprised of aflexible sheet material. The sheet material of seal 110 is sufficientlyflexible such that its width dimensions can be made sufficiently smallby folding along ribs 112 to fit through an opening in a vessel, such asopening created by cutting mechanism 140.

The dimensions of seal 110 of the present invention may be determined,for example, by the vessel into which the seal is inserted and the sizeand purpose of the opening or incision to be sealed. A seal 110 of agiven size and configuration may fit different sizes of vessels andopenings within a certain range, e.g. for coronary artery bypassgrafting. FIGS. 8 a and 8 b show a round seal 110 particularly suitablefor use in sealing a round opening, e.g., a round aortotomy. However, anoval seal configuration may be more suited for sealing an elongatedopening, e.g., an elongated arteriotomy.

As shown in FIGS. 8 a and 8 b, seal 110 may comprise ribs 112. Ribs 112may also be formed of suitable biocompatible material such as, forexample, a biocompatible metal or polymer, which is impervious to blood.A biocompatible material would prompt little allergenic response andwould be resistant to corrosion when placed within the patient's body.Alternatively, ribs 112 may be made of material of suitable rigidity,which is coated with a biocompatible coating.

Ribs 112 may be formed of one or more materials that are more rigid thanthe seal 110, for example, ribs 112 may be made of metal, e.g.,stainless steel or nitinol, while seal 110 may be made of flexibleplastic, e.g., silicone rubber or polyurethane.

The dimensions of ribs 112 may be determined based on the dimensions ofseal 110. For example, as seen in FIGS. 8 a and 8 b, ribs 112 are thesame length as the length of seal 110. However, in one embodiment of theinvention, ribs 112 may be smaller in dimension than seal 110.

Ribs 112 may provide additional rigidity to seal 110 following placementof seal 110. Although in the embodiment of FIG. 8 b, ribs 112 are shownin an “X” configuration on seal 110, ribs 112 may be formed in anysuitable configuration on seal 110, such as a plurality of ribsradiating outward on seal 110 like the ribs of an umbrella.

When placed in the configuration shown in FIG. 8 b, ribs 112 may be usedwith seal tether 114 to help manipulate seal 110 and/or to shape seal110 into a desired configuration, such as the deployment configurationof FIG. 8 a. The flexible sheet material of seal 110 will easily fold inthe direction Fb when seal tether 114 is pulled in direction Fa. Thisallows for easy insertion and retrieval of seal 110 through an openingin the vessel wall. On the other hand, the flexible sheet material ofseal 110 has a natural tendency to unfold and appose the vessel walladjacent to the puncture once seal tether 114 is released.

Seal tether 114 may be formed of any suitable biocompatible material asis known in the art. For example, seal tether 114 may be constructed ofsuture material of appropriate strength so that the material may bepulled to fold seal 110 as described above. Alternatively, seal tether114 may be constructed of biocompatible wire.

As described above, seal delivery shaft 130 may be used to introduceseal 110 into the vessel. In the embodiment of FIG. 7, delivery shaft130 is preferably made of a suitable biocompatible material as discussedabove.

In one embodiment, a seal delivery head 120 (see FIG. 9) may be used inconjunction with seal delivery shaft 130 to introduce seal 110 into thevessel. For example, seal delivery head 120 may be used to help guideseal 110 through tool body lumen 136. Seal delivery head 120 may be madeof a suitable biocompatible material as described above. Seal deliveryhead 120 may be, for example, fixed or coupled onto shaft 130 and can beused to help deploy seal 110 into the opening in the wall of the targetvessel. Seal delivery head 120 may also be constructed of any of themany surgically acceptable materials, for example, various polymers orplastics, stainless steels, nitinol, cobalt alloys, and other iron ornickel containing alloys or titanium.

As seen by comparing FIGS. 8 a and 8 b, seal 110 may be constructed sothat it is deployed in the configuration of FIG. 8 a and then, onceplaced, attains the configuration shown in FIG. 8 b. This is furtherillustrated in FIGS. 10 and 11.

FIG. 10 shows the proximal end of one embodiment of a vessel sealingdevice in accordance with the present invention at 300. Vessel sealingdevice 300 comprises cutting mechanism 340, which is used to manuallycreate a puncture or opening in the recipient vessel. Alternatively,cutting mechanism 140 described above may be used in sealing device 300to create the opening in the wall of the vessel. Cutting mechanism 340is attached to tool body 330. Alternatively, tool body 330 may comprisea blunt end at its proximal end instead of cutting mechanism 140. Adevice 300 that has a blunt ended tool body 330 would be inserted intoan existing incision or opening, for example, an arteriotomy oraortotomy. For example, the opening in the vessel may have been made bya conventional cutting means such as a scalpel or tissue punch. Deliveryshaft 320 is used to push seal 310 and tether 314 through and out of theinner lumen of tool body 330. In one embodiment, delivery shaft 320 maybe configured as a push rod made of one or more biocompatible materialswhich may or may not be non-conductive.

FIG. 11 shows the embodiment of sealing device 300 in situ. Cuttingmechanism 340 may comprise one or more cutting members 342. Cuttingmechanism 340 and cutting members 342 may be made of suitablebiocompatible materials capable of creating a puncture in a vessel. Anyof the many surgically acceptable materials may be used such as variousstainless steels, cobalt alloys, and other iron or nickel containingalloys or titanium. Tool body 330 may also be made of one or morebiocompatible or surgically acceptable materials. As seen in FIG. 11,cutting members 342 are used to create the puncture P in vessel V. Oncethe cutting members 342 and, in one embodiment, a portion of tool body330 have been inserted through puncture P and into vessel V, seal 310may be delivered through inner lumen of tool body 330 by pushingdelivery shaft 320. When seal 310 is in place, seal 310 is released fromdelivery shaft 320 so that seal 310 deploys to an appropriateconfiguration for sealing puncture P in vessel V. After introductioninto the vessel, the blood pressure will sealingly engage seal 310 withthe inside of the wall of the vessel in the vicinity of the puncture P(not shown). Once in the proper place, the transmural pressure in thevessel will keep seal 310 neatly apposed to the inner vessel wall,thereby sealing the puncture or incision. The graft vessel may then beattached to the recipient vessel. Once the anastomosis is almostcomplete, seal 310 may be removed by pulling on tether 314. Upon removalof seal 310, the anastomosis may be completed. Alternatively, seal 310may be made of a dissolvable biocompatible material so it may be left ina sealing position while the anastomosis is completed. A dissolvableseal 310 may then be allowed to dissolve away in the blood stream.

FIG. 12 shows another embodiment of a vessel sealing device inaccordance with the present invention at 500. Vessel sealing device 500comprises a cutting mechanism 540, which is used to manually create apuncture or hole in the recipient vessel. Alternatively, cuttingmechanisms 140 or 340 described above may be used in sealing device 500to create the opening in the recipient vessel. Cutting mechanism 540 isattached to tool body 530. Seal 510 may be delivered through the innerlumen of tool body 530 by pushing on the rigid tether 520. Seal 510 maybe an inflatable seal. In FIG. 12, seal 520 is shown in a partiallydeflated state. Tether 520 may comprise an inner lumen 525 through whichseal 510 may be inflated.

Seal 510 may comprise microscopic pores, thereby allowing seal 510 tofunction as local delivery device. For example, local heparin may bedelivered through lumen 525 to seal 510. Heparin is then delivered fromseal 510 to the anastomosis site thereby reducing the risk of clotformation and local intimal hyperplasia. The local delivery of heparinmay reduce or even abolish any need for anti-coagulation duringanastomosis suturing. Obviating the need for systemic anti-platelettherapy and/or anticoagulation may contribute to a reduction in anybleeding problems. Seal 510 may be designed to deliver one or moreagents, e.g., therapeutic agents, medical agents, biological agents,drugs and/or cells.

Similar to earlier embodiments of the present invention, one or morecomponents of sealing device 500 may be made of one or morebiocompatible materials. Further, one or more components of sealingdevice 500 may be coated with one or more biological agents, e.g., ananti-coagulation agent such as heparin. The coatings may be hydrophilicor hydrophobic as desired.

Inflatable seal 510 may comprise one or more ribs 512 used to providerigidity and/or fluid delivery. For example ribs 512 may have innerlumens and one or more fluid openings for fluid delivery. Inner lumensof ribs 512 may be fluidly connected to one or more lumens of tether520, e.g., lumen 525. Seal 510 may be inflated by introduction of afluid, such as saline, through inner lumen 525 of tether 520.

Seal 510 may comprise one or more shapes inflated and/or deflated. Forexample, in one embodiment seal 510 may have a round inflated shape.Alternatively, seal 510 may have an oval inflated shape. The overallshape of seal 510 may change between an inflated shape and a deflatedshape. For example, seal 510 may have a round shape when inflated and anelongated shape when deflated. Seal 510 may comprise one or moreinflatable chambers or balloons each having similar or different shapes.Inflation and deflation of the one or more chambers or balloons of seal510 may be accomplished via one or more lumens of tether 520. Eachchamber or balloon may be fluidly connected to a separate lumen or asingle lumen may be fluidly connected to two or more chambers orballoons.

FIG. 13 shows an embodiment of seal 510 in situ. Cutting mechanism 540is used to create a puncture P in vessel V. Once the cutting mechanism540 has been inserted within the vessel, seal 510 may be deliveredthrough tool body 530 by pushing on rigid tether 520. Followinginsertion and placement of seal 510, tool body 530 may be removed. Whenseal 510 is in place, fluid may be delivered through inner lumen 525 oftether 520 to inflate seal 510. After introduction into the vessel, theblood pressure will sealingly engage seal 510 with the inside of thewall of the vessel in the vicinity of the puncture P. Seal 510 isrelatively compliant and apposes the wall of vessel V. In its inflatedstate, seal 510 preferably creates a minimal cross-sectional area(minimal obstruction to flow). Depending on the inflation pressure, theinflatable seal 510 adjusts to the radius of curvature of the vessel andseals the opening in the vessel. Graft vessel 550 may then be placedover tether 520 and attached to the recipient vessel V. Once theanastomosis is completed, seal 510 may be deflated and removed throughthe lumen of graft vessel 550.

In some embodiments of the invention, sutures and suture needles forcompleting the anastomosis may guided into proper position by sutureguides located on the surface of seal 510 (not shown). In someembodiments of the invention, the material of seal 510 may be compliant,such that the material of seal 510 gives way to a suture needle, forexample, thereby allowing the suture needle to be passed through graftvessel 550, along the surface of seal 510, and through vessel V, withoutpuncturing seal 510 and producing a leak. The material of seal 510 maybe designed to prevent punctures by suture needles or other sharpobjects used in an anastomosis procedure.

In one embodiment of the invention, an opening is made in the recipientvessel using conventional means, e.g., a scalpel and/or a tissue punchsuch as an aortic punch. A deflated seal 510 may then be placed in theopening. Seal 510 is then inflated to form a fluid tight seal betweenthe balloon and the vessel opening edges. A graft vessel is thenpositioned adjacent the opening in recipient vessel. Sutures are thenplaced to fasten the graft vessel to the recipient vessel. Seal 510 maythen be removed prior tightening of one or more sutures or following thecompletion of the anastomosis. The seal may be removed through the lumenof the graft vessel. Alternatively, the seal may be removed between thegraft vessel and the recipient vessel prior to the tightening of one ormore of the sutures used to connect the graft vessel to the recipientvessel.

FIG. 14 shows yet another embodiment of a vessel sealing device inaccordance with the present invention at 700. Vessel sealing device 700comprises a cutting or puncturing mechanism 740, which is used tomanually create an opening in the recipient vessel. Alternatively, thecutting mechanisms or puncturing mechanisms described above may be usedin sealing device 700 to create the opening in the recipient vessel.Cutting mechanism 740 is attached to tool body 730. Seal 710 may bedelivered through the inner lumen of tool body 730 by pushing on therigid tether 720. Seal 710 may be a “cork-like” seal of a desiredrigidity. Similar to the first embodiment of the present invention, toolbody 730, tether 720 and seal 710 may be made of one or morebiocompatible materials and/or coatings which may be non-thrombogenicand/or hydrophilic.

FIG. 15 shows an embodiment of sealing device 700 in situ. Seal 710 maycomprise a cork-like member or plug. Cutting mechanism 740 may be usedto create the opening or puncture P in vessel V. Once the cuttingmechanism 740 has been inserted within the vessel, seal 710 may bedelivered through tool body 730 by pushing on rigid tether 720. Afterintroduction into the vessel, the blood pressure will sealingly engageseal 710 with the inside of the wall of the vessel in the vicinity ofthe puncture P. The graft vessel 750 may then be placed over tether 720and attached or anastomosed to the recipient vessel. Once graftattachment is completed, seal 710 may be removed.

FIG. 16 shows another embodiment of a vessel sealing device inaccordance with the present invention at 800. Vessel sealing device 800comprises a plurality of “petals,” “blades” or sealing members 810 whichare used in combination to seal an opening in a vessel or organ. Sealingmembers 810 are coupled to shaft 820. FIG. 16 shows a plurality ofSealing members 810 stacked in a delivery configuration, e.g., one ontop of another. Following placement of sealing members 810 within anopening in a vessel, sealing members 810 may be “fanned out” therebysealing the opening from fluid loss. FIG. 17 shows sealing members 810in a partially fanned out configuration, whereas FIG. 18 shows sealingmembers 810 in a completely fanned out configuration. Rotation of handle815 which is coupled to shaft 820 and sealing members 810 in onedirection causes sealing members 810 to fan out while rotation of handle815 in the opposite direction causes sealing members 810 to stack oneach other. Sealing members 810 and shaft 820 may be made of one or moresuitable biocompatible or surgically acceptable materials as discussedabove.

FIG. 19 shows the embodiment of sealing device 800 in situ. Followingthe creation of an opening in vessel V, i.e., puncture P, sealingmembers 810 are passed through puncture P and into vessel V. Sealingmembers 810 are then deployed or fanned out in an appropriateconfiguration for sealing the vessel as shown in FIG. 19. Afterintroduction into the vessel, the blood pressure will sealingly engagesealing members 810 with the inside of the wall of the vessel in thevicinity of the puncture P. Once in the proper position andconfiguration, the transmural pressure in the vessel will keep theconfigured sealing members neatly apposed to the inner vessel wall,thereby sealing the opening, e.g., an arteriotomy or aortotomy. Once theopening is sealed, the graft vessel 850 may be attached to the recipientvessel V. Once the anastomosis is completed, shaft 820 and sealingmembers 810 may be removed through the graft vessel.

FIG. 20 shows an alternative embodiment of vessel sealing device 800 inwhich vessel sealing device 800 includes a pivot, hinge or joint 870 forarticulating or moving sealing members 810 relative to shaft 820. Hinge870 may be actuated remotely, for example, via a cable or push rod 880.

FIG. 21 shows another embodiment of a vessel sealing device in situ inaccordance with the present invention at 900. Vessel sealing device 900comprises a sealing member 910 and a corkscrew 940, which are used tomanually create an opening or puncture in the recipient vessel and toseal the opening. In one embodiment, sealing member 910 includes one ormore cutting blades 912. Corkscrew 940 is located distal to sealingmember 910 on shaft 920. Sealing member 910, corkscrew 940 and shaft 920may comprise or be made of one or more suitable biocompatible orsurgically acceptable materials and/or coatings. Any of the manysurgically acceptable materials may be used such as various plastics,stainless steels, cobalt alloys, and other iron or nickel containingalloys or titanium. Sealing member may be flexible or compliant enoughto be inserted or removed through a vessel.

Corkscrew 940 is screwed into the recipient vessel. Corkscrew 940 may bescrewed until cutting blades 912 cut through the recipient vessel wall,thereby forming an opening or puncture. Once the blade has been used tocreate the opening, sealing member 910 may be left in place to seal thevessel. The graft vessel 950 may then be placed over shaft 920 andattached to the recipient vessel V. Once the anastomosis is completed,corkscrew 940 and sealing member 910 may be removed through the graftvessel.

FIG. 22 shows another embodiment of a vessel sealing device inaccordance with the present invention at 1000. Vessel sealing device1000 comprises a sealing member 1010 which is used to seal an opening ina vessel or organ, especially during the formation of an anastomosis.Sealing member 1010 is coupled to shaft 1020 and handle 1015. The vesselsealing device allows a surgeon to create an anastomosis between twovessels, e.g., between a graft vessel and an aorta vessel, without usinga clamp, e.g., a side-biting clamp. The device may be fed through theconduit or graft vessel, passed thru the opening or puncture in therecipient vessel, e.g., the aorta, and then deployed within the aorta,thereby sealing the opening. The surgeon or an assistant may apply“backpressure” to help occlude the hole. The surgeon can then pass asuture needle around the entire device between the wall of the recipientvessel and the sealing device. The device may have small channels orguides for the suture.

FIG. 22 shows sealing member 1010 rolled up in a delivery configurationon shaft 1020. Following placement of sealing member 1010 within anopening in a vessel, sealing member 1010 may be “unrolled” therebysealing the opening from fluid loss. FIG. 23 shows sealing member 1010in an unrolled sealing configuration. Rotation of handle 1015 which iscoupled to shaft 1020 and sealing member 1010 in one direction causessealing member 1010 to unroll while rotation of handle 1015 in theopposite direction causes sealing member 1010 to roll up. Sealing member1010 and shaft 1020 may be made of one or more suitable biocompatible orsurgically acceptable materials as discussed above. Preferably, sealingmember 1010 is made of a flexible material allowing it to be rolled andunrolled easily.

FIG. 24 shows an embodiment of sealing device 1000 in a deliveryconfiguration inserted through graft vessel 1050. Following the creationof an opening in vessel V, i.e., puncture P, sealing member 1010 ispassed through puncture P and into vessel V. Sealing member 1010 is thendeployed or unrolled into the appropriate configuration for sealing theopening in the vessel as shown in FIG. 25. After introduction into thevessel, the blood pressure will help sealingly engage sealing member1010 with the inside of the wall of the vessel in the vicinity of thepuncture P. To help engage sealing member 1010 with the inside wall ofthe vessel, an appropriate force, as mentioned above, may be exerted onsealing device 1000 in a direction away from the vessel, e.g., thesurgeon may slightly pull back on the device to help more tightly engagesealing member 1010 with the edges of the opening in the vessel. Once inthe proper position and configuration, the transmural pressure in thevessel will help keep the configured sealing member neatly apposed tothe inner vessel wall, thereby sealing the opening, e.g., an arteriotomyor aortotomy. Once the opening is sealed, the graft vessel 1050 may beattached to the recipient vessel V, for example using one or moresutures 1060 as shown in FIG. 25. Once the anastomosis 1062 is completedas shown in FIG. 26, sealing member 1010 may be rolled back into itsdelivery configuration. Sealing member 1010 and shaft 1020 may then beremoved through graft vessel 1050.

In one embodiment of the invention, seal member 1010 may comprise one ormore ribs 1012. Ribs 1012 may be formed of suitable biocompatiblematerial such as, for example, a biocompatible metal or polymer, whichis impervious to blood. A biocompatible material would prompt littleallergenic response and would be resistant to corrosion when placedwithin the patient's body. Alternatively, ribs 1012 may be made ofmaterial of suitable rigidity, which is coated with a biocompatiblecoating. Ribs 1012 may be formed of one or more materials that are morerigid than the sealing 1010, for example, ribs 1012 may be made ofmetal, e.g., stainless steel or nitinol, while seal 1010 may be made offlexible plastic, e.g., silicone rubber or polyurethane. Ribs 1012 mayprovide additional rigidity to seal 1010 following placement of seal1010. As shown in FIG. 25, ribs 1012 may be formed in any suitableconfiguration on seal 1010, such as a plurality of ribs radiatingoutward on seal 1010 like the ribs of an umbrella.

Similar to earlier embodiments of the present invention, one or morecomponents of sealing device 1000 may be made of one or morebiocompatible materials. Further, one or more components of sealingdevice 1000 may be coated with one or more biological agents, e.g., ananti-coagulation agent such as heparin. The coatings may be hydrophilicor hydrophobic as desired.

In some embodiments of the invention, sutures and suture needles 1060for completing the anastomosis may be guided into proper position bysuture guides located on the surface of seal 1010 (not shown). In someembodiments of the invention, the material of seal 1010 may becompliant, such that the material of seal 1010 gives way to a sutureneedle, for example, thereby allowing the suture needle to be passedthrough graft vessel 1050, along the surface of seal 1010, and throughvessel V, without puncturing seal 1010 and producing a leak. Thematerial of seal 1010 may be designed to prevent punctures by sutureneedles or other sharp objects used in an anastomosis procedure.

As illustrated in various embodiments described above, the seal memberof vessel sealing device may be delivered through an inner lumen of thetool body and placed adjacent an opening, e.g., incision or puncture, ina recipient vessel, thereby sealing the opening in the vessel. Followingplacement of the seal member, the tool body may be removed, leaving theseal member in place to seal the opening. The tool body may or may notcomprise a cutting mechanism for creating an opening in the recipientvessel. The seal member may be attached to a tether or shaft. A graftvessel 350 may then be positioned adjacent the opening in the recipientvessel. The graft vessel may be positioned over the tether or shaft soas to position at least a portion of the tether or shaft within thelumen of the graft vessel (see FIG. 27). Upon completion of theanastomosis, the seal may be removed through the lumen of the graftvessel. Alternatively, the graft vessel may be positioned adjacent theopening in the recipient vessel so that the tether or shaft ispositioned between the recipient vessel and the end of the graft vesselto be anastomosed to the recipient vessel (see FIG. 28). Prior tocompletion of the anastomosis, the seal may be removed from the openingbetween the graft vessel and the recipient vessel. Following removal ofthe seal, the anastomosis may be completed.

FIG. 29 shows an alternative embodiment of a vessel sealing device inaccordance with the present invention. In this embodiment, seal 710 andtether or shaft 720 are delivered through inner lumen 136 of tool body135. Tool body 135 is coupled to cutting mechanism 140 which comprisesone or more electrodes coupled to power conductor 145. Power conductor145 conducts power to cutting electrodes 140. As described above, powerconductor 145 may be connected to a power source by a power connectorpin. Cutting electrode 140 is used to form an opening or incision invessel V. While power is being provided to cutting electrode 140,cutting electrode 140 is advanced through the wall of vessel V (see FIG.30), thereby creating an opening in vessel V. Seal 710 is advanced orpushed through lumen 136 of tool body 135, through cutting electrode 140and into vessel V (see FIG. 31). Power may be provided to cuttingelectrode 140 at any time while seal 710 is advanced through lumen 136of tool body 135, through cutting electrode 140 and into vessel V.Cutting mechanism 140 is coupled to the proximal end of tool body 135 soas to allow cutting mechanism 140 to change from a closed cuttingconfiguration to an open delivery configuration. Therefore, as seal 710is pushed into cutting mechanism 140, cutting mechanism 140 opens into adelivery configuration, thereby allowing seal 710 to move into vessel V.Once seal 710 is positioned in vessel V, cutting mechanism 140 may beremoved from the opening in vessel V (see FIG. 32). Seal 710 may be leftin place, thereby sealing the opening in vessel V, until a graft vesselis anastomosed to vessel V, as described above.

FIG. 32 shows an alternative embodiment of seal member 710 in accordancewith the present invention. In this embodiment, seal 710 may be used todeliver fluids and/or agents to the blood stream and/or vasculartissues. The fluids and/or agents, e.g., therapeutic agents, medicalagents, biological agents, drugs and/or cells, may be delivered throughan inner lumen of shaft 720 and out through one or more fluid openings713. Fluid openings 713 may be fluidly coupled to one or more innerlumens of shaft 720. One or more biological glues, adhesives or sealantsmay be delivered, for example to help seal the anastomosis. RF energymay be delivered to the anastomosis to help close or seal theanastomosis.

FIG. 33 shows an alternative embodiment of a tissue punch 1100 that maybe used in accordance with the present invention. In this embodiment,tissue punch, e.g., an aortic punch, 1100 having an internal lumen 1136may be used to create a puncture or opening within a recipient vessel.The seal member of the vessel sealing device in accordance of thepresent invention may be delivered to the opening in the vessel throughinternal lumen 1136.

FIG. 34 shows an alternative embodiment of vessel sealing device 100that may be used in accordance with the present invention. Vesselsealing device 100 as shown in FIG. 34 includes a suction line or vacuumpassage 155 coupled to inner lumen 136 of tool body 135. Suction line155 may be coupled to a source of suction or vacuum. As used herein, theterms “vacuum” or “suction” refer to negative pressure relative toatmospheric or environmental air pressure in the operating room. Suctionapplied to the area of cutting mechanism 140 may be used to removetissue debris or blood from the opening formed in the recipient vessel.For example, suction may be applied via suction line 155 so that anegative pressure is created in inner lumen 136. As cutting mechanism140 cuts through tissue, thereby creating an opening in the vessel, anytissue debris created from the cutting procedure is drawn into innerlumen 136 and into suction line 155. Therefore, suction may be used toprevent tissue debris from entering the patient's blood stream, therebypreventing complications, e.g., clotting, downstream of the newly formedopening. Suction may also be used to position and/or hold vessel sealingdevice in position against or adjacent the recipient vessel.

FIG. 35 shows one embodiment of a method for sealing a vessel inaccordance with the present invention at 1200. As seen at block 1210, apuncture or opening is created within a first or recipient vessel usingone or more of the cutting mechanisms described above. Alternatively, aconventional cutting means such as a scalpel or tissue punch, e.g., anaortic punch, may be used to create the opening. As seen at block 1220,a seal member is inserted into the opening. In one embodiment of thepresent invention, the seal member may be delivered into the openingthrough an inner lumen of a tool body as described above. Alternatively,the seal member may be delivered into the opening without use of a toolbody. As seen at block 1230, the seal is deployed to an appropriateconfiguration to seal the opening. For example, the seal may be deployedto engage with the inside of the wall of the recipient vessel in thevicinity of the opening. Once in the proper place, the transmuralpressure in the recipient vessel will keep the configured seal neatlyapposed to the inner vessel wall, thereby sealing the opening, e.g., anarteriotomy or aortotomy. As seen at block 1240, a second or graftvessel is attached, e.g., via sutures, to the recipient vessel while theseal is in place. As seen at block 1250, once the anastomosis of thegraft vessel to the recipient vessel has been completed, orsubstantially completed (e.g. all or most of the sutures are in place),the seal is removed. In one embodiment the seal is removed through thegraft vessel. In an alternative embodiment, the seal is removed betweenthe graft vessel and the recipient vessel.

For example, bypass grafting may be performed to provide adequate bloodsupply to an organ or tissue with impaired blood supply. In bypassgrafting, the end of an extra vessel (the graft vessel) is connected,e.g., end-to-side or side-to-side, to the recipient vessel, e.g, anartery, downstream of the obstruction in the recipient vessel. Toestablish this connection, i.e. the distal anastomosis, the recipientvessel may first be opened via an incision or puncture. Next, the sealof the present invention is inserted through the opening and deployedthereby sealing the opening from blood loss. Next, the exit or distalend of the graft vessel is coupled, e.g., via suturing or other bondingmethod, to the recipient vessel. The seal may then be removed from therecipient vessel.

The inside of the graft vessel is generally sutured to the inside of therecipient vessel. The rationale of this precise anastomosis suturing isthat the inner lining of the vessels (the endothelial lining) isanti-thrombogenic, whereas the outer layer is highly thrombogenic.Thrombosis at the transition of the graft vessel to the recipient vesselreduces the cross-sectional area of the lumen at the junction and hencejeopardizes the quality of the anastomosis. Narrowing or stenosis of theanastomosis limits the maximum blood flow through the bypass graft.

In a proximal anastomosis, the entrance (proximal end) of the bypassgraft needs to be connected to a pressure source of oxygenated bloodsuch as an artery or an aorta. If a natural artery can serve as bypassgraft, like e.g. the internal mammary artery in coronary artery bypassgrafting, only the distal anastomosis needs to be made. Sometimes,however, the internal mammary artery is used as free graft or the radialartery is used as arterial conduit and a proximal anastomosis has to bemade. Venous bypass grafts always require a proximal anastomosis,because their transformation to an arterial conduit requires connectionto a source of arterial blood.

It will be appreciated by those skilled in the art that while theinvention has been described above in connection with particularembodiments and examples, the invention is not necessarily so limited,and that numerous other embodiments, examples, uses, modifications anddepartures from the embodiments, examples and uses are intended to beencompassed by the claims attached hereto. The entire disclosure of eachpatent and publication cited herein is incorporated by reference, as ifeach such patent or publication were individually incorporated byreference herein.

We claim:
 1. A method of constructing an anastomosis between a firstvessel and a second vessel comprising: providing a device comprising anelectrode for creating an opening in a vessel and a seal having aplurality of seal members for sealing the opening in the vessel;positioning the electrode adjacent a wall of the first vessel; applyingsufficient energy to the electrode to form an opening in the firstvessel; delivering the seal into the opening in the first vessel whereinthe plurality of seal members are in a stacked first configuration;rotating a handle coupled to a shaft and to the seal members in a firstdirection to radially spread the plurality of seal members about an axisof the opening into a fanned-out second configuration to seal theopening; attaching the second vessel to the first vessel to form theanastomosis; rotating the handle in a second direction to arrange theplurality of seal members in the stacked first configuration; andremoving the seal from the opening.
 2. The method of claim 1 wherein thefirst configuration is a low-profile configuration.
 3. The method ofclaim 1 wherein the second configuration is an expanded-profileconfiguration.
 4. The method of claim 1 further comprising deliveringone or more fluids to the first vessel while the seal is in a secondconfiguration.
 5. The method of claim 1 further comprising deliveringone or more agents to the first vessel while the seal is in a secondconfiguration.
 6. A method of constructing an anastomosis between afirst vessel and a second vessel comprising: providing a sealingassembly comprising a seal and a shaft wherein the seal includes aplurality of seal members; positioning the shaft so that at least aportion of the shaft is positioned within the second vessel; creating anopening in the first vessel; inserting the seal through the openingwherein the plurality of seal members are in a stacked firstconfiguration; rotating a handle coupled to the shaft and to the sealmembers in a first direction to radially spread the plurality of sealmembers about an axis of the opening into a fanned-out secondconfiguration to seal the opening; attaching the second vessel to thefirst vessel to form the anastomosis; rotating the handle in a seconddirection to arrange the plurality of seal members in the stacked firstconfiguration; and removing the seal through the second vessel.
 7. Themethod of claim 6 wherein the first configuration is a low-profileconfiguration.
 8. The method of claim 6 wherein the second configurationis an expanded-profile configuration.
 9. The method of claim 6 furthercomprising delivering one or more fluids to the first vessel while theseal is in a second configuration.
 10. The method of claim 6 furthercomprising delivering one or more agents to the first vessel while theseal is in a second configuration.